Typewriting machine



June 15 1926.

J. H. BARR TYPEWRITING MACHINE I Filed July 11, l923 fii-ii INVENTSS I iillii WITNESSES Rug L AT T URNEY Patented June 15, 1926.

ilhilTED i ih'i'hlhi'l' @FFICE.

JOHN H. BARR, G1 ITHACA, NEW YORK, ASSIGNOE 13-5) REMINGTON TYPEW'RITER COIE'LPAJBT'EZ, OF ILIQlf-T, NEW YQBK, A UOEPOEATIQN OF NEW YORK.

TYPEWRITING Ii'IACHINE.

Application filed July 11, 1323.

My invention relates to carriage motor or spring drum mechanism for typewriting machines and its chief object is to provide new and improved spring drum mechanism which is especially adapted for use in wide carriage machines though not limited to such use.

To the above and other ends which will hereinafter appear, my invention consists in the features of construction, combinations of devices, and arrangements of parts hereinafter described and particularly pointed out in the claims.

In prior constructions various expedients have been resorted to in order to compensate for the variation in the pull of the main spring, such for example, as providing a drum having a snail or cam surface over which the usual draw band or strap runs; but such a construction has the disadvan- Q9 of limiting; themovement to less than .i igle revolution of the draw band drum, at least where a band or strap is employed.

lly my present invention these 'diiliculties' are overcome by introducing gearing between the spring drum and the band drum so designed that the torque on the shaft of the band drum will be substantially constant during one revolution of the turning element of the spring drum. In order to permit of using a cylindrical drum for the draw band and one of a comparatively small diameter which will yet permit of writing a line longer than would be equivalent to one revolution of the draw band drum, additional gearing may be employed including members having such a ratio that the revolutions of the band drum may be a desired number ot times the corresponding revolutions of the spring drum element or memher. )i': course, the spring in order to produce more than one revolution of the draw baud drum for a single revolution of the spring drum element must be correspondingly strengthened: that is, it the draw band makes two revolutions for one revolution of the spring drum element, as in the present se, the spring should be twice as strong it it were directly connected. My invent'on will be described in detail in connection with the accompanying drawings wherein Figure 1 a fragmentary rear elevation of a spring drum mechanism embodying my invention, together withv certain associate parts;

Serial No. 650,756.

Figures 2 and 3 are vertical sectional views taken respectively on planes indicated by the section lines 11 and 22 in Figure 1 and looking in the direction of the arrows at said lines.

My invention is applicable to typewriting machines generally, but in the present instance i illustrated as applied to a typewriting machine of the character more fully disclosed in my prior Patents Nos. 1,413,312, and 1,419,901. Also variousconstructional details of the spring drum mechanism proper correspond with those disclosed in the patent to Edwin E. Barney No. 1,430,208, granted September 26, 1922. The main fame of the aforesaid machine supports a transversely disposed bed plate or angular trough 1 which is fixed to the side'portions of said main frame,'said trough being provided with tracks or raceways, the lower one whereof is shown in the present instance and numbered 2. The tracks co-operate through anti-friction rollers 3 with a traveling carriage comprising an inclined rear bar or plate which is composed of upper and lower grooved ars connected by cross webs, the lower bar a only being shown together with a portion of an inclined cross web The traveling carriage comprising the rear carriage plate or bar t, 5, generally resembles the carriage disclosed in my prior Patent No. 1,419,901 aforesaid but preferably is of the wide carriage style providing a support for a long or wide platen.

The carriage motor mechanism comprises a circular band drum 6 having a flange 7, the drum being vertically arranged and projecting upward through a slotway 8 in the bed plate. A hollow bearing stud 9 secured to the drum receives the pivot pin 10 of an angular pawl 11, one arm of which projects outward through an opening 7 in the flange 7. This pawl arm assists to connect the band drum with the traveling carriage, said arm having secured to its outer extremity one end of a flexible band or strap 12 whose opposite end is detachably connected to a hook 13 on the carriage. The

. pawl 11 is provided with a draw spring 13 lit) ing 7. The drum 6 is provided with a flanged hub 15 which is suitably secured to the web of the drum and is mounted on the rear end portion of a shaft 16 which projects rearward beyond a flanged bearing member 18 that is received and supported by the rearinost arm 19 oil? a bracket which further COll'lPl'lSOS a parallel arm 20 and a cross portion or connection. 21. The bracket is formed of sheet metal and bent to a U- shape and detachably secured in inverted position by screws 22 to the under face of the bed plate, the bed plate being thickened and suitably machined at this point to provide a suitable contact surface. Said bracket carries and supports all of. the spring drum mechanism, the parts constituting said mechanism being detachable and attachable with the bracket. The shaft 16 bears in both arms 19 and 20 of said bracket through suitable bearing members mounted on said arms, the rear member 18 having been previously referred to, and the forward member 23 being in the form of a collar or bushing which has a. reduced cylindrical portion 2 1 that is staked or otherwise secured in the arm 20 providing a bearing of suitable width and stability for the shaft 16. The rear bearing member 18 of said shaft has a flanged portion or head 25 disposed in rear of the bracket arm 19, the outer face oi? said head 25 being formed with an annular flange 26 within which loosely tits the front end portion of the flanged hub 15. The rear end portion of the shaft 16 is reduced and threaded at 16 and receives a nut 27 which prevents displacement of the drum 6 and its hub 15, said drum and hub turning with the shaft 16. The bearing member 18 25, 26 is suitably secured in the bracket arm 19, and surrounding the annular portion is a ratchet wheel 28 which is suitably fixed to the hearing member. The angular pawl 11 is in the same vertical plane as the stationary ratchet wheel 28 and is adapted to co-operate with the teeth thereof to prevent rotation of the drum (3 under impulse oi the main spring, should the band 12 break or when said band is detached from the hook 13. It will be understood that when the pawl 11 is released from the pull of the carriage, the spring 13 will become etl ective to turn said pawl on its pivot 10 and throw the pawl tooth into engagement with the ratchet wh el 28 to lock the spring driun mechanism against running down The motor drum proper or main spring drum is likewise supported on the bracket 1921 in parallelisnrwith the band drum by means of a horizontal shaft. 29 said shaft being arranged at the right of the shaft 16 and parallel therewith. As. appears from Fig. 2 the forward end portion oisaidshatt 29v bears in a bearing ripening, in thee-rm 19 of the bracket, the rear end portion of said shaft having an extend-ed bearing provided by a hub or bushing 30 which is suitably fixed in the bracket arm 20 and projects forward therefrom. Real-ward displacement of the shaft 29 in its bearings is prevented by a collar 81 which is secured to the shaft by a set screw 32 forward of the hub 80. The rear end portion of the shaft 29 projects beyond the bracket arm 20 and has mounted on it the spring drum which comprises a shell or casing 33 having a circular flange 3 1-, the casing being open towards the rear and receiving a cage containing the main spring. Said cage comprises a body or web 35 having a series of angularly disposed fingers 36 at its edge which are adapted to interlock with slotways in the shell 33, 3% as set forth in the aforesaid Barney Patent lo. 1,430,208. The coiled or convolute main spring 37, which is contained within the shell and when in place is confined between the casing wall and the web 35 of the case, engages at its outer end with. a pin or hook 38 projecting inside the cage and secured thereto. The inner end of the main spring 3'? is secured to a hook 39 which pro-- ects from a thimble 4-0 which has a closed end 41 formed with a hole which enables the t-hiinble to he slipped over the projecting end portion of the shatt 29, said thimble fitting over a collar 42 which is secured to the shatt by a cross pm 43. The thiinble is forced tot-urn with the shaft and collar in any convenient way. For example, in the present instance the end portion of the shaft 29 has a flattened side or sides 4% and the hole in the thimble has correspondingly flattened sides which engage closely with the sides 4%. The collar 42 projects forward through an opening in the wall of the shell 33am! that portion of the collar outside said shell and between it and the bracket arm 2) provides a support tor a ratchet wheel 4-5 which is spaced forward from the shell bya washer it), the ratchet wheeh washer and shell being rigidly secured tog-ether as by rivets 47. A double toothed pawl 48 provided with a suitable linger piece 4-9 piv otcd on a shoulder screw 50 secured to the upper portion 01 the bracket arm 20, said pawl (Io-operating with the ratchet vheel -15 to hold it normally against rotation under the impulse of the main spring. The con struction is such that the ratchet wheel. the casing 33, 34,, the cage 35. 36 and the outer end or. the main spring 37 are normally held. from movement by the pawl. thus anchoring the outer end of the main spring and per nltting it to wind and unwind through the connection of its inner end to the shaft 29. It willbe understood that the main spring may be wound up to increase its tension by turning theshe l and, cage towards the right, as viewed in Fig. l, and that the tension may be reduced by actuating the pawl handle {l9 to permit the two teeth of the pawl 48 operating alternately to allow the ratchet wheel to turn or escape step-by-step. During such alteration of the main spring tension by the turning of'the drum, the shaft 29 will not be affected. On the other hand, during the run or travel of the carriage under the pull of the main spring, the spring drum shaft will turn to transmit the power while the shell and the cage will remain motionless. In other words, the rotary element or member of the spring drum device, when the latter operates to move the carriage, is the shaft 29 and not the drum itself, thus reversing some other constructions wherein the rotary member is the drum proper, the shaft being the stationary element in such a case.

It will be observed that the band drum 6 with which the carriage is flexibly connected is separately mounted from the main spring 37 and its drum. My invention comprises novel connections between the two drums or drum members, said connections being designed to produce two main results, first, to compensate for the gradual weakening of the main spring as the carriage travels from right to left and the spring drum member or shaft 29 turns to unwind the spring; and, second, to increase the amount of rotation of the band drum relative to the extent of turning of the drum member 29 and unwinding of the main spring so that a band drum of comparatively small diameter such. as that shown in the drawing may be employed in connection with a wide carriage which has a comparatively long run or travel. The compensating means before re ferred to comprises in the present case compensating gearing which is arranged between the main spring rotary member or shaft 29 and a countershaft 51 which is mounted on the bracket arms 19 and 20 below the main spring shaft, said shaft 51 hearing in bushings or collars 52'and which are respectively staked or otherwise secured to the lower portions of the bracket arms 19 and 20 and project inward towards each other from said arms. The compensating gearing comprises two gears 54 and 55 which constantly intermesh, the gear 54- being mounted forward of the bracket arm 19 on the projecting end of the shaft 29, a headed screw threaded into said shaft preventing displacement of the gear 54 therefrom. The gear 54 is held rigid with the shaft in any suitable way, as by squaring, the end of the shaft at 57 and correspondingly squaring the hole in the gear. Said gear 54; may be provided with a slight boss or hub to maintain it separated from the face of the bracket arm 19. The gear 55 which is secured to the projecting end of the shaft 51 forward of the bracket 19 and is similarly spaced from said bracket by a thickening or boss is held from displacement by a headed screw 58 which is threaded into the end of the shaft 51. The end portion of said shaft may be squared at 59 and the hole in the gear similarly squared to force the gear to turn with he shaft. The pair of gears 54 and 55 are not circular gears but instead are developed on spiral pitch lines being what are sometimes termed scroll, snail or spiral gears. They are so designed that the torque on the counter siaft will be substantially constant during one revolution of the spring drum, the radius of the gear 5a decreasing as the power of'the main spring decreases and the radius of the gear 55 correspondingly increasing with the decrease of the radius of gear 54-.

The counter shaft 51 serves as a power shaft having transmitted to it through the gears 54L and 55 the power of the main spring and in turn transmitting this power to the band drum 6, 7. The means for connecting the counter or power shaft 51 to the band drum comprises a gear train composed of two members. One of these members is a large circular gear wheel 60 having a hub 61 which is mounted on the power shaft 51, the hub receiving a set screw 62 whereby the gear wheel 60 is fixed on its shaft. The

other member of the gear train is a small circular or spur gear 63 provided with a hub 6-1 and which is mounted on the drum shaft 16 behind the bearing 18, 25, 26, the gear 68 being fixed to the shaft by a set screw 65 threaded through the hub 6 1 and abutting against the shaft 16. It will be noted that endwise displacement of the shaft 16 left ward in its bearings will be prevented by the gear wheel 63 contacting with the rear face of theb'earing 18. The spur gears 60 and 63 are in the ratio of two to one, that is, the gear 60 has twice many teeth the 63 so that one revolution of the gear 60 wiil cause two revolutions of the gear 63.. In other words, each revolution of the power shaft 51 will cause two revolutions of the shaft 16 and of the band drum 6. 7, these two turns of the drum being sufficient to take care of the travel of a wide carriage, the flexible connection or band 12 of course winding twice around the flange 7 of the band drum.

It will be observed that by reason of the novel connections between the two drums or drum members comprising trains of gearing from each to the power or counter shaft, means are provided for compensating for the weakening of the spring and maintaining a substantially constant pull on the carriage as it runs or moves from right to left; and that means are also provided for increasing the extent of rotation of the band drum relative to the rotation of the power member .or counter shaft from, wh ch said band drum In a receives its impulse, thereby enabling the diameter or" the band drum to be maintained within practicable limits even for a wide carriage.

it will further be observed that there are provided parallel circular drums, one connected to the carriage and one to a convolute spring, in combination with means between the drums for maintaining a. substantially constant pull on the carriage; that the main shaft has connected to it a convolute main spring, that the counter shaft is connected to the main shaft through conipensating connections whereby the variable pull on the carriage, due to the. diii'erent positions it occupies, is substantially equalis d; and that there are two trains of gearing between the band drum or carria e drum and the main or power shaft one train bein l 1 2: equalizing gearing and tne other using transmitting gearing which preferably inul t-ipiies or increases the speed.

various changes ma be made without departing from my invention.

hat I claim as new and desire to secure by Letters Patent is In a typewriting machine, the combination of a carriage, a circular drum, a shaft on which said drum is mounted, aconvolute spring within said drum and having one end connected thereto, the other end of said spring being connected to said shaft, sec ond circular drum arranged in parallelism to the first drum and connected to said carriage, and means between the two drums for maintaining a substantially constant pull on said carriage at the difi'erent points in its travel while affording a plurality of revolutions ot said second circular drum.

2. in a typewriting machine, the combi nation of a traveling carriage, a main shaft, a convolute main spring connected thereto, a counter shaft, a circular drum connected thereto and with which the carriage is flea; ibly connected, and connections between the shafts tor con'ipensating for the variable pull on the carriage due to the ditiercnt positions it occupies during its travel.

in a typewriting machine, the combination of a traveling carriage, a drum with which the carriage is flexibly connected, a main spring shaft, and connections includ ing pair of scroll or spiral gears between said drum and said shaft.

l. In a typewriting machine, the con1- bination of a traveling carriage, a carriage main spring, a shaft, and connections between said main spring and said shaft comprising a pair of scroll or spiral gears.

In a typewriting machine, the combination of a traveling carriage, a drum connected therewith, a shaft, gears connectii'ig said drum with said shaft to increase the rotation of said drum relative to said shaf'i't, a spring drum member, and connections :3 tween said spring drum member and shaft, said last recited connections compi. ing a pair or scroll or spiral gears.

6. In a t-ypewriting machine, the combination of a traveling carriage, a drum incinber connected thereto, a spring dru incinber, a shaft, compensating connect us between one of said n'iembers and aid shaft for equalizing the pull on said carnage, and speed varying connections between the other of said members and said shalt to increz the rotation of said band drum member relative to said spring drum member.

'7. In a typewriting machine, the combination of a traveling carriage, a drum connected thereto, a power shaft, and two trains of gearing between said drum and said power shaft, one of said trains being equalizing gearing to maintain substantially constant tension, the other of said trains being speed multiplying gearing.

8. In a typewrit-ing machine, the combination of a traveling carriage; and carriage driving mechanism comprising two drums, shafts concentric with said drums, and connections between said shafts comprising a pair of spiral gears and also transmitting gears.

9. In a typewriting machine, the rombizuu tion of a carriage, a spring drum raving a flexible. connection said carriage, a drum shaft, a spur gear on said shaft, an internieshing spur gear of larger diameter. a shaft for said intern'ieshing gear, a spiral gear on said shaft, an intcrineshin gear, a shaft on which said internxc iii spiral gear is mounted, and power means for turning said shaft.

10. In a typewriting machine, the combination of a carriage mounted to travel on the frame of the machine, a bracket detachably secured to the frame of the machine, a band drum connected to said carria a spring drum, a shaft, a train of gears connecting said spring drum with said shait, and a train of gears connecting said baud drum with said sha it said spring drum. said band drum, said shaft and said trains of gears all being mounted on said bracket and being detachable therewith.

Signed at the borough of Manhattan. city of New York, in the county of New .forl: and State of New Yorlr, this 7th day of July, A. D. 1923.

I J OHN H. BARR. 

